1. Field of Invention
This invention relates generally to fastening devices that simplify joining structural members of a building under construction and more particularly to a locking bolt adapted to aid making a connection between a vertical column and horizontal beams.
2. Prior Art
Difficulties of joining structural members during erection of a building have long been recognized and continue because there is no universally accepted solution.
One example of an assembly particularly adapted for joining sections of structural angle is shown in U.S. Pat. No. 3,499,258. On ends of the angle sections to be joined are block-shaped fittings that extend beyond the respective angle ends. Each fitting has a calibrated hole positioned between a pair of plain holes. With the fittings placed end-to-end, a drift pin is inserted through the now aligned calibrated holes. Nut-bolt assemblies then are placed in the fitting plain holes to hold the fittings and related angle sections together.
U.S. Patent No. 4,254,542 then discloses a nut and bolt assembly for forming an initial loose connection between a horizontal floor beam and a vertical column of a building under construction. The bolt has a hex-shaped head on an end of a large diameter shank portion. This shank portion then is connected to a small diameter threaded end by a tapered section. Because the threaded end of the bolt has a diameter smaller than an opening in a column, initial alignment between the bolt and column opening need not be exact. Once inserted, the bolt is held in place by a nut having a sleeve that fits against a web of the column.
Additionally, locking-type fasteners that include a toggle have been known and in use for many years.
One early locking-type fastener is set out in U.S. Pat. No. 1,075,759 and includes a headless cylindrical body. Near an outer end of the body are perpendicularly offset, transversely positioned long and short slots. A locking lever is pivotally secured in the long slot by a pivot pin having ends slidably disposed respectively in the short slots. The lever pivot pin is longitudinally offset to be closer to an inner end of the lever. For use an outer end of the fastener passes through an opening in a support structure, such as a wall, until the inner end of the locking lever clears an inner side of the wall. Because of the lever pivot is offset, the lever then rotates from the long slot. Next, the fastener body is drawn inward. Serrations on a bottom edge of the lever seat against the wall inner side as a top edge of the lever fits against an outer end of the long slot.
U.S. Pat. No. 1,340,470 discloses another locking-type bolt having a threaded, cylindrical-shaped body. On each side of an outer end of the body is a recess having an L-like shape. One recess faces up while the other recess faces down. Pivotally secured in each recess is a complementary shaped toggle. For use the body of the bolt is pressed through aligned openings in spaced apart inner and outer plates, for example. Once the toggles clear an inner side of the inner plate, the toggle in the downward facing recess rotates out of its recess. The bolt then is secured by seating the rotated toggle against the inner plate. Once seated, toggle rotation is inhibited by contact between a shoulder of the toggle and a shoulder of its recess.